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This study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.

Objective measures of heart failure are not related to subjectively assessed symptom burden.

Point out that the study suggests that objective measures, often used as endpoints in clinical trials or to assess treatment efficacy, cannot be used as surrogates for symptom burden in patients with heart failure.

Among patients with moderate-to-severe heart failure from a single clinic, three objective measures -- left ventricular ejection fraction, pulmonary capillary wedge pressure, and cardiac index -- were not significantly associated with physical symptoms, either individually or in combination with each other, according to Quin Denfeld, BSN, RN, a doctoral student at Oregon Health & Science University (OHSU) in Portland.

Thus, the objective measures, which are often used as endpoints in clinical trials or to assess treatment efficacy, cannot be used as surrogates for symptom burden in patients with heart failure, Denfeld reported at the American Association of Heart Failure Nurses meeting here.

Symptom burden should be measured along with the objective variables, she said.

"This is important because it informs quality of life and the ability of patients to monitor symptoms," Denfeld said. "Awareness of symptoms is a key component of heart failure self care. Recognition of heart failure-specific symptoms and then response to these symptoms can improve self-care abilities and thus potentially avert repeated hospital admissions, improve survival, and improve health-related quality of life."

On the whole, previous research has suggested that there is not a strong relationship between objective measures of heart failure pathogenesis and physical symptom burden in patients with heart failure. Even so, management strategies and assessments of treatment efficacy are typically based on objective tests.

To explore the relationship between the objectively assessed factors and symptom burden, Denfeld and colleagues performed a secondary analysis of data collected during a study of symptoms among adults treated at the heart failure clinic at OHSU.

All 167 patients included in the current analysis completed the Heart Failure Somatic Perception Scale (HFSPS), which measures nonspecific symptoms, such as fatigue and weight gain, and acute symptoms like dyspnea. The scale has been shown to work well in patients with advanced heart failure.

The mean age of the patients was 56. Most were male (61%), white (87%), and had non-ischemic heart failure (62.3%).

The objective measures were obtained during a routine catheterization before or after enrollment in the study. Among all the patients, the average ejection fraction was 27.3%; the average pulmonary capillary wedge pressure was 18.4 mm Hg; and the average cardiac index was 2.09 L/min/m2.

The average HFSPS score was 24.6 (out of a possible 90), "indicating that a significant amount of patients had physical symptom burden," Denfeld said.

None of the three objective measures was associated with scores on the HFSPS (P>0.05 for all).

The only variable that was associated with symptom burden was the Duke Activity Status Index, which measures functional capacity. Worse functional capacity was related to increased symptom burden (P<0.001).

Denfeld said that clinical trials in the heart failure population should measure symptom burden along with other clinical endpoints, and that it might be interesting for future studies to look for physiological indices that are related to symptom burden.

In addition, she said, future research might also address sex differences in symptom burden. Women, for example, tend to have higher ejection fractions and might have a different awareness of symptom.

The study was supported by the Office of Research on Women's Health and the National Institute of Child Health and Human Development through the Oregon BIRCWH program and by the NIH/National Institute of Nursing Research (NINR) Research Training in Individual and Family Symptom Management Pre-Doctoral Fellowship Grant.

Reviewed by Robert Jasmer, MD Associate Clinical Professor of Medicine, University of California, San Francisco

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